Macular degeneration, also called age-related macular degeneration (AMD), is a condition affecting the eye that primarily occurs in people over age 65. Macular degeneration is the leading cause of vision loss in this age group. The condition results in the loss of clear, central vision.
There are two forms of macular degeneration disease: dry AMD and wet AMD. Each has its own set of symptoms, clinical course, and treatment options. Both forms of the condition result in damage to the macula, the most light-sensitive part of the retina. The macula is located at the back of the eye, and its job is to process fine details and assist in central vision.
Dry AMD is the most common form of macular degeneration disease, affecting about 90% of AMD sufferers. In dry AMD, cells in macula begin to atrophy, causing the slow development of a blind spot in central vision. Blurred vision that improves in bright light, along with a small but growing blind spot in central vision, are two early warning signs of dry AMD. In some cases, dry AMD progresses so slowly that a person may not realize vision loss is progressing. This is why it’s important to have regular eye exams. Fortunately, the AREDS vitamin formula developed by researchers at the National Eye Institute can stall the progression of intermediate macular degeneration and prevent or slow further vision loss.
Wet AMD affects only about 10% of those with age-related macular degeneration, but results in the majority of serious AMD-related vision loss. Wet AMD is caused by hardening and thickening of the retina, resulting in cracking or breaking of the retina and oxygen deprivation to retinal tissues. The body responds by creating new blood vessels to the retina. These weak blood vessels are prone to leaking and bleeding, thus the term wet or “exudative” AMD. The newly grown blood vessels push on and displace the macula, much in the way that tree roots can displace a sidewalk. Early symptoms of wet AMD include a blind spot in central vision, and a distortion in the perception of object shape due to macular displacement. A common manifestation of this is the perception of straight lines as being crooked. Wet AMD is a far more rapidly progressing disease than dry AMD, with fewer effective treatment options. While laser surgery, phototherapy, and injections can be used to treat the condition, it often progresses despite these interventions.
If you have symptoms of macular degeneration or other types of vision loss, it’s important to schedule an eye exam right away. Your eye doctor can use a variety of painless exam techniques to assess your eye health. These techniques include a visual acuity test, measuring pressure within the eye, and performing a dilated eye exam to directly observe the structures of the eye for any abnormalities.
Photo by Agostino Martinelli